From 579ad107a69690efc17401c487b06e89d9e8a91d Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 25 Oct 2016 21:10:20 +0200 Subject: [PATCH] ash: [EXPAND] Removed herefd hack Upstream commit: Date: Sun, 11 Nov 2007 15:00:06 +0800 [EXPAND] Removed herefd hack The herefd hack goes back more than a decade. it limits the amount of memory we have to allocate when expanding here-documents by writing the result out from time to time. However, it's no longer safe because the stack is used to place intermediate results too and there we certainly don't want to write them out should we be short on memory. In any case, with today's computers we can afford to keep the entire result in memory and write them out at the end. function old new delta redirect 1268 1264 -4 ash_main 1485 1478 -7 subevalvar 1157 1132 -25 growstackstr 54 24 -30 argstr 1192 1154 -38 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-104) Total: -104 bytes Signed-off-by: Denys Vlasenko --- shell/ash.c | 61 +++++++++++++++++++---------------------------------- 1 file changed, 22 insertions(+), 39 deletions(-) diff --git a/shell/ash.c b/shell/ash.c index 3f1405d81..527abc7b1 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -1399,7 +1399,6 @@ struct globals_memstack { char *g_stacknxt; // = stackbase.space; char *sstrend; // = stackbase.space + MINSIZE; size_t g_stacknleft; // = MINSIZE; - int herefd; // = -1; struct stack_block stackbase; }; extern struct globals_memstack *const ash_ptr_to_globals_memstack; @@ -1408,7 +1407,6 @@ extern struct globals_memstack *const ash_ptr_to_globals_memstack; #define g_stacknxt (G_memstack.g_stacknxt ) #define sstrend (G_memstack.sstrend ) #define g_stacknleft (G_memstack.g_stacknleft) -#define herefd (G_memstack.herefd ) #define stackbase (G_memstack.stackbase ) #define INIT_G_memstack() do { \ (*(struct globals_memstack**)&ash_ptr_to_globals_memstack) = xzalloc(sizeof(G_memstack)); \ @@ -1417,7 +1415,6 @@ extern struct globals_memstack *const ash_ptr_to_globals_memstack; g_stacknxt = stackbase.space; \ g_stacknleft = MINSIZE; \ sstrend = stackbase.space + MINSIZE; \ - herefd = -1; \ } while (0) @@ -1605,10 +1602,6 @@ static void * growstackstr(void) { size_t len = stackblocksize(); - if (herefd >= 0 && len >= 1024) { - full_write(herefd, stackblock(), len); - return stackblock(); - } growstackblock(); return (char *)stackblock() + len; } @@ -5893,33 +5886,28 @@ static int evaltree(union node *, int); static void FAST_FUNC evalbackcmd(union node *n, struct backcmd *result) { - int saveherefd; + int pip[2]; + struct job *jp; result->fd = -1; result->buf = NULL; result->nleft = 0; result->jp = NULL; - if (n == NULL) + if (n == NULL) { goto out; + } - saveherefd = herefd; - herefd = -1; - - { - int pip[2]; - struct job *jp; - - if (pipe(pip) < 0) - ash_msg_and_raise_error("pipe call failed"); - jp = makejob(/*n,*/ 1); - if (forkshell(jp, n, FORK_NOJOB) == 0) { - FORCE_INT_ON; - close(pip[0]); - if (pip[1] != 1) { - /*close(1);*/ - copyfd(pip[1], 1 | COPYFD_EXACT); - close(pip[1]); - } + if (pipe(pip) < 0) + ash_msg_and_raise_error("pipe call failed"); + jp = makejob(/*n,*/ 1); + if (forkshell(jp, n, FORK_NOJOB) == 0) { + FORCE_INT_ON; + close(pip[0]); + if (pip[1] != 1) { + /*close(1);*/ + copyfd(pip[1], 1 | COPYFD_EXACT); + close(pip[1]); + } /* TODO: eflag clearing makes the following not abort: * ash -c 'set -e; z=$(false;echo foo); echo $z' * which is what bash does (unless it is in POSIX mode). @@ -5928,15 +5916,14 @@ evalbackcmd(union node *n, struct backcmd *result) * [EVAL] Don't clear eflag in evalbackcmd * For now, preserve bash-like behavior, it seems to be somewhat more useful: */ - eflag = 0; - evaltree(n, EV_EXIT); /* actually evaltreenr... */ - /* NOTREACHED */ - } - close(pip[1]); - result->fd = pip[0]; - result->jp = jp; + eflag = 0; + evaltree(n, EV_EXIT); /* actually evaltreenr... */ + /* NOTREACHED */ } - herefd = saveherefd; + close(pip[1]); + result->fd = pip[0]; + result->jp = jp; + out: TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", result->fd, result->buf, result->nleft, result->jp)); @@ -6343,7 +6330,6 @@ subevalvar(char *p, char *varname, int strloc, int subtype, char *str; IF_ASH_BASH_COMPAT(char *repl = NULL;) IF_ASH_BASH_COMPAT(int pos, len, orig_len;) - int saveherefd = herefd; int amount, resetloc; IF_ASH_BASH_COMPAT(int workloc;) int zero; @@ -6352,12 +6338,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype, //bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)", // p, varname, strloc, subtype, startloc, varflags, quotes); - herefd = -1; argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ? (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0), var_str_list); STPUTC('\0', expdest); - herefd = saveherefd; argbackq = saveargbackq; startp = (char *)stackblock() + startloc; @@ -7391,7 +7375,6 @@ expandarg(union node *arg, struct arglist *arglist, int flag) static void expandhere(union node *arg, int fd) { - herefd = fd; expandarg(arg, (struct arglist *)NULL, EXP_QUOTED); full_write(fd, stackblock(), expdest - (char *)stackblock()); }